Manually cleaning of façades and windows of multi-story buildings is ineffective, dangerous and weather dependent. Different kinds of automatic cleaning equipment have been developed.
U.S. Pat. No. 3,895,406 discloses an automatic window washer having a washing module riding in vertical tracks on the face of a building and is controlled by a unit mounted on the roof of the building. The automatic washing operation of the components of the washing module is controlled by electric, fluidic and pneumatic systems.
CN2423041 discloses a high altitude cleaning machine including a machine body and a rubber wheel. A winding engine is used to hang the cleaning machine on the surface of a multi-story building and to vertically move the cleaning machine. The gravity force acting on the machine is converted into thrust force to thrust the machine towards the surface of the building. The rubber wheel is caused to rotate by the friction of the surface of the building through the action of gravity, and power is generated to drive the cleaning brush to rotate. The device includes a cleaning agent spray pipe for spraying the cleaning agent on the window.
U.S. Pat. No. 5,707,455 discloses an automatic cleaning apparatus of an exterior wall of a building. The apparatus includes a container for housing washing water, and a pump driven by a motor. The washing water is pumped through a water pipe and sprayed against the window. The used washing fluid is recovered.
U.S. Pat. No. 3,080,592 discloses an automatic window washer recovering used cleaning liquid, which also filters the recovered cleaning liquid. The window washer includes a drive motor driving a plurality of rotating sponges, a liquid storage reservoir, and a pump operated by the drive motor for delivering cleaning liquid from the reservoir to the sponges. The cleaning liquid is sprayed on the edges of the sponges when the sponges rotate. A squeegee wiper is arranged above the sponges for wiping off used cleaning liquid from the window.
U.S. Pat. No. 3,775,804 discloses a window wall washing device for multi-story buildings. The device includes an enclosed chamber for recovering cleaning fluid. From the enclosed chamber the cleaning liquid is recirculated for reuse through a liquid reservoir. An inclined interior wall cooperates with a vertical plate to form a trough in which recovered cleaning liquid is collected from drain tube, which communicates at its upper end with the trough and at its lower end with the reservoir. A liquid pump draws the cleaning liquid from the reservoir through an inlet hose and delivers the cleaning liquid under pressure to a plurality of nozzles, which spray the cleaning liquid on the window. One of the nozzles is arranged below the brush and one of the nozzles is arranged above the brush, so that the windows are wet before the brushing takes place. This improves the result of the cleaning, since the dirt on the window is dissolved or at least loosen by the cleaning liquid so that the brush can easily remove the dirt. However, the use of hoses to transport the cleaning liquid over several floors may cause problems, for example, by causing leakage because of friction or with tangling.
GB172,425 discloses a power driven window cleaning device. This cleaning device includes a cleaning module arranged on a handle adapted to be held by a human, and accordingly the device is not suitable for cleaning multi-story buildings. The device includes brush rotatably mounted in a casing, and a motor for rotating the brush. A front part of the brush is adapted to be in contact with the window during the cleaning. A tank for housing a cleaning liquid extends longitudinally of the casing and adjacent the brush. The tank is provided with an opening in its top wall, which opening is normally closed by a plug, so at to permit a washing solution to be poured into the tank. The tank is further provided with an opening through its front wall, which communicates with a wick tube, in which operates a wick. The wick is submerged in the solution in the tank and projecting so as to rest against the bristles of the brush and feed the cleaning liquid thereto be capillarity. The tank is located behind the brush and the wick feeds the cleaning liquid to a rear part of the brush. A disadvantage with this device is that due to the rotation of the brush, most of the cleaning liquid is removed from the brush before it reached the window to be cleaned. Further, this device does not provide a spraying of the cleaning liquid on the window, before the brushing takes place. This results in a poor cleaning of the windows.
The above mentioned cleaning apparatuses are complicated machines, and this is a disadvantage when it comes to operation, service and repair on a device in the environment normally exposed to heavy wind, water and pollution. Further, all of them rely on electricity to operate the washing apparatuses, for example, for driving a rotating brush or sponges, or for driving pumps for spraying the cleaning fluid on the windows. This is a particularly disadvantage if the cleaning machine is to be used for cleaning multi-story buildings due to difficulties to supply the power to the cleaning machine.